Blast-furnace



(No Model.) ZSheets-Sheet 1.

, H. KENNEDY.

BLAST FURNACE Patented Aug. 4', 1891.

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WITNESSES (No Model.)

2 Sheets---Shet 2. H. KENNEDY. BLAST FURNACE.

Patented Aug. 4,1891.

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UNITED STATES PAT NT OFFICE.

HUGH KENNEDY, OF SHARPSBURG, PENNSYLVANIA.

BLAST-FU RNACE.

SPECIFICATION forming part of Letters Patent No. 457,202, dated August4, 1891. Application filed October 10, 1890. Serial No. 367,706. (Nomodel.)

To all whom it may concern.-

Be it known that I, HUGH KENNEDY, of Sharpsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in the Construction of Blast-Furnaces, of which thefollowing isa full, clear, and exact description, reference be- 1ng hadto the accompanying drawings, forming part of this specification, inwhich- Figure 1 is a front view, partly in section, of the lower part,boshes, and hearth of a blastfurnace constructed with my improvement.Fig. 2 is a horizontal section, partly on the line II II of Fig. 1 andpartly on the line II II of the same figure. Fig. 3 is a front view, andFig. 4 a section on the line IV IV of Fig. 3, of my improvedwater-cooled plates for the cinder-notch. Fig. 5 is a front view, andFig. 6 a section on line VI VI of Fig. 5, of my water-cooled plate forthe tap-hole. Fig. 7 is a 7 front View, and Fig. 8 a section on the lineVIII VIII of Fig. 7, of my water-cooled plate for the walls of thehearth.

Like symbols of reference indicate like parts in each.

The plate-iron casing for the hearth of the furnace is illustrated inFigs. 1. and 2. A cylinder of plate metal is formed of curved sheets ofsteel a a'such, for example, as boilerplate-of a height extending fromthe hearthstone up to Within a short distance of the boshes and belowthe tuyere-openings b b. These plates are preferably made in two layersor courses, excepting where the furnaceopenings are situate, where theymay be reenforced, as at a a in Fig. 2, by the use of three orfourlayers. The joints of the plates run in'a Vertical direction, andinstead of being lapped one edge over the edge of the adjoining plate,the edges are brought together, and vertical strips 0 are placed overthe joints, to which strips the plates are firmly riveted. The platesare made of such width as to break joint, as shown in Fig. 2. Suitableopenings are made in the plates for the tap-hole cl and the cinder-notche. The casing-cylinder being thus formed is placed over or upon ahearth-stone f, and on each side of the openings for the tap-hole andcinder-notch, inside of the casing-cylinder and resting against itsinner surface, I place vertical cast-iron cooling-plates g, (theconstruction of which I will presently describe,) the height of which ispreferably the same as that of the'casing-cylinder and the width such asmay be found convenient. These plates are of arc shape in cross-section,as shown in Figs. 2, 4, 6, and 8, and of the same degree of curvature asthe inside of the cylindrical casing, as shown in I to the casing,instead of placing a single layer of iron around the Wall of the hearthafter it is built, as is usual, the thickness of masonry composing thewall h of the hearth may be reduced, and the structure is renderedstronger, and the cracking of the Wall by expansion and contraction isin a great measure prevented. A water-pipe n, supplied from a pipe Z,extends around the furnace, and is adapted to discharge a stream ofwater upon the plates a a. The masonry is built within the plates asclosely to the interior thereof as possible, and as the plates areriveted securely in place around the furnace the effect of the heat of Hthe hearth is to expand the masonry into Very close cont-act with theplates and to cause the cooling influence of the water which flows overthe plate to be exerted on the masonry in the most effective manner. Inaddition to the water-cooling afforded by this device, I employ a circleof horizontally-arranged Water-cooled plates 1) p, constructed in themanner of bosh-plates, which are built in the furnace-wall at the hearthbelow the level of the tuyeres and as near as possible to the level atwhich the molten iron rises in the hearth. Heretofore very greatdifficulty has been experienced from the liability of furnace-walls toburn out at the hearth in curved lines extending down from the tuyeresuntil the wall becomes so thin as to cause the metal-incasing jackettostretch and thus to weaken the hearth-wall, so asto permit the escape ofthe molten metal, which attacks the incasingjacket and cracks it, thusnecessitating frequent repairs, and by enlargement of the furnacerequiring the use of more fuel. I have discovered, however, that byusing the watercooled bosh-plates in the walls below the tuyeres andusing the tightly-fitted externallyro cooled incasing-jacket, this isprevented, the furnace-walls are preserved, and may be used intact for along period of time.

In the use of furnaces as heretofore built the action of the blast andthe wearing of the stock cause the walls to be eaten away in a curveextending from the tuyeres to the hearth. By placing the circle ofwater-cooled plates below the tuyeres and as low as possible, so thatthey shall not touch the iron line, the brick-work between the tuyeresand plates is preserved and the curve of cutting in the short distancebetween the plates and the hearth is very much shortened, so that it isquite possible to hold the hearth intact for an indefinite time by meansof the incasingjacket. This has not been possible in prior furnaces, inwhich the curve of cutting at the hearth soon becomes so deep as toendanger the breaking out of the molten iron and to cause a great wasteof heat and fuel in operating the furnace. The advantages of thesewater-cooling devices for preserving the-walls will be appreciated bythose skilled in the art. They will be found to be the means of 5 savingof labor and time and diminish in a great measure the dangers attendingthe operation of a blast-furnace.

In Figs. 3 to 8the Water-cooled plates gare shown in front view andsection on a larger scale than in Figs. 1 and 2. They are formed ofcast-iron of any desired shape and size by casting in a mold, in thecavity of which are placed and supported U-shaped water-pipes 2', themetal being cast around the pipes in a manner well known in the art ofcasting, and which needs not to be here described, By the expressionU-shaped pipes I mean to designate sections of pipe placed vertically inthe cooling-plates with thetwo extremities extending above the top edgesof the plate at the same end, as at t" t" in Figs. 3, 5, and 7, eachsection of pipe between its two extremities being curved in such way asmay be necessary or desirable to distribute the water-space throughoutthe body of the plates g. Thus, in Fig. 7, where the plate 9 is designedto be used in a part of the hearth of a furnace where there are noopenings from the outside, each section of pipe I is simply bent in Uform, so as to bring both ends of the pipe to the top of the plate. InFig. 5, where the plate is intended to surround the tap-hole, an opening01 of suitable size and shape being made in the plate for that purpose,each section of pipe 01 is bent so as to pass around the taphole, asshown in the figure, and in Fig. 3,

which represents two plates surrounding the cinder-notch, the pipes iare curved, so as to traverse the wider as well as the narrowerportions. If a single plate were used for the cinder-notchinstead oftwo, the pipes might pass from one side to the other of the opening, asin Fig. 5. Each adjacent pair of pipes (excepting the inlet-pipe 1 andoutletpipe 2) is connected together by elbow-joints andconnecting-pieces 7c it, so as to form a continuous water-pipeconnection. For example, in Fig. 5 cold water, entering at theprojecting end 1 of pipe 1', traverses the whole series of pipes, asindicated by dotted lines, until it passes out at the projecting end 2.These projecting ends 1 and 2 are the inlet and outlet pipes for thecold water, which is introduced from a circular waterpipe Z, surroundingthe furnace at any suitable point, (see Fig. 1,) the inlet-pipes 1 beingconnected with the cold-water supplyl and the outlet-pipes 2 beingcarried to or connected with any convenient escape pipe 1 or trough. Thespecial advantage of the arrangement of the pipesz' in thecooling-plates,

' as just shown and described, is that if any of the pipes should becomestopped or choked they may be cleared out by connecting the inlet-pipes1 with a steam-boiler and passing steam through the series of pipes, or,in case any of the pipes should vbe rendered useless by the burning ofthe platesas, for example, pipes 2' 'L nearest to the cylinder-notch ortap-hole, these pipes may be cut out of the series by removing theelbow-joints k and coupling-pieces 7c and making a new arrangement whichshall cut out the section of pipe which has become destroyed by burningor otherwise.

In addition to the vertical cooling-plates just described, I place acast-iron coolingcap-plate m, constructed as before described, in ahorizontal, or preferably in a somewhat inclined, position over thetap-hole d of the furnace, as shown in Figs. 1 and 2. The dotted linesin Fig. 2 indicate the course and position of the internal water-pipes.If the plate on is inclined, it should incline downward toward theoutside of the furnace. The pipes 3 and 4, connecting with the interiorpipes of the cap-plate m, are the inlet-pipes from the water-supply pipeZ and the outletpipe for the heated water.

I claim 1. In blast-furnaces, the combination, with the masonryhearth-Wall and tuyeres, of wa: ter-cooled plates arranged in a circlehorizontally within the furnace-wall below the tuyere-level, pipes forconducting water to said plates, and a water-cooled external casingextending from substantially the level of the water-cooled plates to thebase of the furnace, substantially as and for the purposes described.

2. In the construction of blast-furnaces, the combination, with thehearth-wall and IIO tuyeres, of the cylindrical casing with oo01- I11testimony whereof I have hereunto set ing-plates set in contact with theinner surmy hand this 6th day of October, A. D. 1890. face of saidcasing below the tnyere-level at the points exposed to great heat, pipesfor HUGH KENNEDY. 5 conducting water to said plates, and masonry\Vitnesses:

or brick-work built Within said casing, sub- WV. B. CORWIN,

stantially as and for the purposes described. THOMAS W. BAKEWELL.

